Fix to_rgb_color_list when passing rgba colors

[janosh]

Closes #3477.

Code PR

• I have read through the contributing notes and understand the structure of the package. In particular, if my PR modifies code of plotly.graph_objects, my modifications concern the codegen files and not generated files.
• I have added tests (if submitting a new feature or correcting a bug) or modified existing tests.
  No tests for to_rgb_color_list at all yet but not necessary as dependent function create_annotated_heatmap is about to be deprecated (see below).
• I have added a CHANGELOG entry if fixing/changing/adding anything substantial.

[janosh]

Another probable issue is that to_rgb_color_list does not handle hsl(a) colors at all, even though create_annotated_heatmap does. Should we add a case for that?

[janosh]

I have added a CHANGELOG entry if fixing/changing/adding anything substantial.

Does this require a changelog entry?

[nicolaskruchten]

Hi, and thanks for your pull request! Yes, this probably needs a changelog entry.

I should note that in the next release of this library, we will be marking create_annotated_heatmap as deprecated, as px.imshow() will be able to add text to heatmaps natively, and all the colour-handling will happen in the Javascript layer so as to be more robust.

[janosh]

Good to know. So does px.imshow on current master already handle text? If so I might switch right away.

[janosh]

@nicolaskruchten This is ready for review.

[nicolaskruchten]

Thanks @janosh ! Yes, I've just merged the new changes to px.imshow to master, and I've marked create_annotated_heatmap as deprecated, so I'd rather not make any new modifications to it now, if that's OK.

[janosh]

It's still a fix and would allow me to release some code that relies on this. Merging fixes even to deprecated code makes sense imo.

[nicolaskruchten]

does this now still work with rbg(...) and rgba(...) both ?

[janosh]

Yes, it does. Tested it. As I mentioned, doesn't handle HSL(A) yet.

[nicolaskruchten]

OK. After this next release I won't be accepting any more PRs to this deprecated code so let's not work on any HSL stuff please :)

[nicolaskruchten]

OK, thanks!

[janosh]

Thanks for merging!

[janosh]

I should note that in the next release of this library, we will be marking create_annotated_heatmap as deprecated, as px.imshow() will be able to add text to heatmaps natively, and all the colour-handling will happen in the Javascript layer so as to be more robust.

px.imshow doesn't seem to provide a way to set xgap/ygap. Also would be cool if the https://plotly.com/python/imshow examples included one with pandas where a df with a text column is used to render hover tooltips. Doesn't feel like imshow is ready to replace create_annotated_heatmap yet.